End-thrust bearing for grinding-wheel spindles



' Nov. 6, 1928. 1,690,425

0. H. NORTON END THRUST BEARING FOR GRINDING WHEEL SPINDLES OriginalFiled July 5. 1920 WW UMUOWIOL Mum Charles H Norfon Patented Nov. 6,1928.

UNITED STATES PATENT OFFICE.

CHARLES H. NORTON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTON COM-PAN'Y, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

END-THRUST BEARING FOR GRINDING-WHEEL SPINDLES.

Original application filed July 3, 1920, Serial No. 393,913. Divided andthis application filed August 1,

1922. Serial No. 579,031.

My invention relates to a grinding machine and.more particularly to anend thrust hearing for the grinding wheel spindle. This case is adivision of my prior application 6 Serial No. 393,913, filed July 3,1920, entitled Grinding machines, and relates to an improvement in myprior Patent No. 1,189,861, dated July 4, 1916.

'One difliculty encountered in the modern 1 precision grinding machinehas been that the wheel spindle, which is run at full speed andsubjected to high frictional forces, is likely to stick from overheatingor lack of proper lubricationor improper adjustment of the bearings, duelargely to the parts being so constructed and arranged that while thelengthwise expansion of a spindle may be considerable yet the end thrustbearings are not capable of permitting such movement and still providingthe required degree of tightness when the machine is running undernormal working conditions.

It is accordingly an object of my invention to produce an improved endthrust bearing for the wheel spindles of such machines which willminimize the deleterious eflects of expansion due to heating of theparts and permit proper lubrication of the bearing and which will beconvenient of adjustment to take up unavoidable wear and yet will notpermit the operator to apply excessive pres sure to the bearing toprevent proper lubrication and stick the spindle. Further objects willbe apparent in the following disclosure.

In the drawings which illustrate a specific embodiment of my inventionFigure 1 is a vertical section partly broken away of a grinding wheelspindle provided with my improved end thrust bearings:

Fig(.12 is a section on the line 2-2 of Fig. 1' an Fig. 3 is a viewsimilar to Fig. 1 on the line 3-3 of Fig. 2.

A grinding wheel spindle may comprise, as shown in my prior Patent No.1,191,986 of July 25, 1916, two bearing surfaces separated by a pulley,these surfaces being su1tably mounted in radial bearings. The grindingwheel is mounted at one end of this spindle and end thrust bearings areprovided at the opposite end. Referring particularly to the drawings,the wheel spindle 10, the left-hand portion of which is broken away. ismounted in suitable radial bearings 11 held in the casing 12 of thewheel slide. These bearings 11 may be constructed of spaced membershaving partial cylindrical bearing surfaces, the spaces between thesemembers serving for the passage of oil from the right-hand part of thedevice, as illus trated, to the space 13 where the oil may escape to areservoir and be returned for further use.

In order that the end thrust or lo'ngitudi nal play in the grindingwheel spindle may be delicately adjusted, I provide the constructionillustrated in the drawings. As there shown the wheel spindle isprovided with a reduced portion 15 outside of the radial bearings. riesa sleeve 16 provided with a flange 17 spaced by a considerable distancefrom the radial bearings and the larger portion of the spindle. Thissleeve with its flange is held rigidly on the shaft by a pair of locknuts 18. The projecting end of the wheel slide 12 is bored to receive acap 20 which is attached to the wheel slide hub by suitable screws 21.This cap 20 has an inwardly projecting portion 22 provided with aradially extending flange 23 which projects into the space between theenlarged portion of the wheel spindle 10 and the flange 17 but is spacedfrom the enlarged portion of the spindle as illustrated. In order toprolong thewearing qualities of this inwardly projecting flange 23, itis provided with a hardened steel collar 25 non-rotatably secured to theflangeby a pin 26.

It will be apparent that this collar 25 provides a rigid abutment totake the thrust of the spindle to the left. The thrust of the spindle inthe other direction is taken up by a similar hardened steel collar 28secured by a pin 29 to the end of a cup shaped block 30 which isadjustable outwardly and inwardly by means of a screw 31 which isprovided with a knurled head 32 and a lock nut This screw is threadedinto a cover plate 35 which is secured to the cap 20 by screws 36. Thecup shaped block 30 is prevented from turning in the cap 20 by means ofa key 38, as shown in Fig. 1.

In order to insure proper lubrication of the end thrust bearing) and theradial bearings, I provide a suite le oil circulating sys- This reducedportion cartem which includes the passages 40 and 41 in the wheel slidecasing and a transverse passage 42 in the cap 20, which open through ahole 43in the cylindrical wall of the cup shaped block 30 to theinterior thereof adjacent the lock nut 18. The hardened steel collars 25and 28 and the inwardly projecting flange 23 are provided withlongitudinal oil passages 44. The collars are also provided with radialpassages 45 for the circulation of oil around the flange 17. Hence oilwhich is poured by a suitable pump through the pipe 40 is carriedthrough the various circulatory passages adjacent the thrust bearingsurfaces and thence to the spaces between the radial bearings and to t espace 13 within the wheel slide casing, from which the oil may bereturned to these passages, thus insuring a perfect lubrication of thebearings. In order that it may be determined whether the oil is flowingproperly or not, I also provide a small oil chamber 46 covered with aglass plate 47 which serves as a sight opening for viewing the How ofoil. The flow of oil is indicated by the arrows in Fig. 3.

By means of this construction the end thrust bearings may be adjusted toa fine degree of precision and it will be practically impossible for oneto so tighten the bearings as to stick the wheel spindle. This isaccomplished by means of the thumb screw 31 which is provided with aknurled head 32, which is made purposely round and knurled so as toprohibit the use of the usual wrench and make it difiicult for theoperator to set up the screw other than by hand. The size of the head ofthe screw is such that if the operator turns it by hand he cannotnormally put suflicient pressure on the bearings to cause them to stick.As a particular feature in this construction, I have separated the flane 17 and its associated parts from the radial arings, in order to reducethe amount of elongation and contraction of the material between the twoabutment collars 25 and 28, which causes looseness and tightnessrespectively in the bearing. By the new arrangement, I insure that suchchange in size is reduced to a negligible amount and that the bearings\Vlll always be properly lubricated and cannot be stuck by excessiveheat generated by friction therein.

It will also be noted that dust and dirt are fully excluded from thethrust bearings and that the adjustment of the end play may beaccomplished without in any way disturbing the remaining portions of thebearings. Furthermore, the wearing parts are of simple construction andmay be economically replaced when worn. In order to properly adjust thebearings it is merely necessary to start the machine running and thenwhen the spindle has become warmed up to adjust the thumb nut by handonly by a gentle pressure, after which the check nuts are tightened upalso by hand.

Having thus described my invention, it will be evident that changes andmodfications may be made therein b those skilled in the art withoutdeparting rom the spirit and scope thereof as set forth in the claim,and I do not wish to be otherwise limited to the details hereindisclosed.

What I claim is A grinding wheel mounting comprising a casing, a radialbearing mounted therein, a wheel spindle mounted in and extending beyondthe end of the radial bearing, a flange on the extension of the spindlespaced from the end of said radial bearing, an

annular thrust receiving flange rigidly mounted on the casing and deendin between the flange on the spin le an the radial bearing and spacedfrom the latter, an adjustably positioned outer thrust receiving cupengaging the opposite side of the spindle flange and readily accessiblemeans to adjust the position of said cup during rotation of the spindle.

Signed at Worcester, Massachusetts, this 27th day of July, 1922.

CHARLES H. NORTON.

